Is Rotom Ishihara's favorite Pokemon? Is that why it got 5 forms in Platinum, then got type retcons for no reason, still hogs 4 unique type combos all to itself, got the Rotom Pokedex, and all of the Rotom "forms" we see in the Sword & Shield overworld?

The last reference to Ishihara's favorite being Exeggutor is from 2000, well before Rotom even existed.